METHOD OF CREATING RECYCLE IN LIQUID EXTRACTION PROCESS (VERSIONS) Russian patent published in 2000 - IPC

FIELD: chemical engineering. SUBSTANCE: invention can be, in particular, applied in petroleum processing on plants for selective purification of oil fractions with various solvents such as phenol, furfurol, and N-methyl-2-pyrrolidone. Recycle in washing section of multistage extraction system in countercurrent extraction of mixture with selective solvent is created by feeding into washing section of extraction system a part of raffinate solution taken off from extraction section of extraction system or part of raffinate obtained after regeneration of solvent from mentioned raffinate solution. EFFECT: increased yield of raffinate and driving force of separation of interacting phases in washing section of extraction system. 2 cl, 8 dwg, 6 tbl